The present invention relates to a method and apparatus for detecting characteristics of a communication channel. In particular, the present invention may be utilized to determine if a communication channel is digital end-to-end. For example, the present method and apparatus may determine whether an Integrated Services Digital Network ("ISDN") to ISDN connection is all digital. Alternatively, the present method and apparatus may determine whether an ISDN to T1/E1, or T1/E1 to T1/E1, connection is all digital. Impairments in the digital connection may also be detected by the apparatus and method of the present invention.
For ISDN to ISDN connections, some known systems send digital data over a channel that is billed as analog. Such systems do not verify that the channel is actually digital before sending the data. Rather, such systems may simply follow the practice of "just trying" to blindly send digital data over what may be an analog link and "seeing" if it works. If the channel is believed to be digital, but is actually analog, the connection will fail.
For ISDN to T1/E1, or T1/E1 to T1/E1, connections, no known methods or apparatii provide high speed data transfer. If an ISDN to T1/E1, or T1/E1 to T1/E1, call is made with prior art systems, analog communication is typically provided (speeds up to 33.6 kbps full-duplex). In accordance with standard industry practice, communication occurs as if only over an analog link.
Accordingly, it would be desirable to have an improved method and apparatus for determining characteristics of a communication channel.